Drilling apparatus



A. ARUTUNOFF DRILLING APPARATUS Oct. 6, 1953` 2 sheets-sheet 1l Filed oet. 15. 1949 T0 FIG. 3a.

Oct. 6, 1953 A ARUTUNOFF 2,654,572

DRILLING APPARATUS Filed Oct. l5. 1949 2 Sheets-Sheet 2 140 Il: ll

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Patented 'Oct 6, 1953 UNITED STATES PATENT OFFICE DRILLING APPARATUS Armais Arutunoi, Bartlesville, Okla.

Application October 15, 1949, Serial No. 121,579

(Cl. Z55-4.8)

Claims.

The present invention relates in general to the drilling of oil wells, and it deals more particularly with an improvement in a drilling tool of the type shown in my co-pending applications Serial Nos. 711.959,. now U. S. Patent Number 2,609,182, filed November 23, 1946, and 60,709, filed November 18, 1948.

In those applications l disclosed a drilling unit suspended on a cable which is capable of being payed out to advance the drill downwardly into the earth, the suspended unit including the motor connected to the drill through the reduction gearing and a pumpalso driven by the motor for circulating drilling mud.

It is important that working parts, such as the circulating pump and the reduction gearing, be readily replaceable at the nrst sign of wear, and one of the objects of the present invention is to provide a self-contained unit including all of these working parts, which unit is. easily atn tached to the motor and easily disconnected therefrom for servicing.

Another important object is to provide a drilling device of the character indicated, that is capable of receiving a core bit and has means to facilitate removal of the core sample from the formation after it hasy been drilled.

Using a cable-suspended drilling tool of the type shown in my earlier applications, it has been customary in thepast, after drilling a core, to reel in the cable thereby to. elevate the tool with a core retained in the core barrel; however, because the core is connected at its base to the native formation, a considerable strain is iinposed on the cable in breaking it loose. One of the main objects oi this invention, therefore, is to provide an arrangement for breaking oif a core without subjecting the cable to this severe strain. An important feature resides in the pro vision of a lost motion connection between the drilling unit proper and the core barrel whereby the unit may be given an initial upward momen turn before the core barrel is lifted, the full inertia of the upwardly moving mass of the device being utilized to. impart an upward blow to the core barrel. or bit.

Another object of the invention is to provide an improved form of reduction gearing and means for sealing the same against intrusion of drilling fluid or other foreign matter. To this end l employ multi-stage planetary gearing and a novel arrangement for maintaining the successive stages in proper working relationship.

Other and further objects of the invention, together with the structural features of novelty whereby the objects. are achieved, will appear in the course `of the following description of the invention.

In the accompanying drawings` which form a part of the specification and are to be read in conjunction therewith, and in which likel reference numerals are employed to indicate like parts of the various views:

Fig. l is a side elevation of my drilling device showing the same., in a bore hole,

Figs. 2 and 2.a are enlarged longitudinal cross section of the upper portion of the drilling unit,

Figs. 3 and 3a are enlarged longitudinal cross sections of the lower portion of the drilling unit, and

Fig. 4 is an enlarged longitudinal cross section of the core bit and barrel.

Referring first to Fig. 1, my drilling device is an elongated cylindrical unit comprising an upper assembly A and a lower assembly B, the two being threaded together at their junction and supported by a cable 5. Itl will be understood that the cable is connected at its upper end to a derrick or hoist (not shown) by which the cable may be payed out during a drilling operation and reeled in after the drillingl operation in order to lift the drilling unit to the surface.

The upper assembly A includes section Ai housing an electrical motor, a bailer section A2 above the motor and an anti-rotation device A3 having shoes for gripping the wall of the well bore to prevent rotation of the drill as a whole during the drilling operation; the construction of the anti-rotation device is fundamentally like that shown in my aforementioned applications and since it forms no part of the present invention,

it has not been shown in detail here.

The lower assembly B includes ve separate sections connected end to. end, section B1 housing the pump for circulating drilling iiuid, section B2 containing the speed reduction gearing, section B3 supporting the main thrust bearings, section B4. comprising the lost motion knocker mechanism,v and section B5 housing the main bearings for the drill shaft.

Referring now to Figs. 2 and 2u whichshow ther upper assembly A, the motor is in a sealed housing 6 spaced inwardly from the outer shell A1 and its shaft 'l extends vertically downward from the housing to a point approximately level with the bottom of the shell. The annular space 8 around the motor housing forms a fluid passageway communicating at its4 lower end through a duct 9` with the open upper end of the lower assembly B.Y The annular passageway 8 communicates at its upper end' with a, standpipe it extending centrally through the bailer shell A2. The power leads l l for the motor extend through a packing gland I2 in the motor housing upwardly through the pipe lil and thence to the surface, preferably being incorporated in the supporting cable 5 as explained in my prior applications.

Thev central pipe i has perforationsv i3 at its upper endthese being disposed opposite perforations I4 in the outer shell, the two sets of perforamy device is detailed in Figs. 3 and 3a. This as sembly is provided with external threads il at A' its upper end and to receive the internally downwardly extending motor shaft 'i' by means of a splined coupling i8 is the pinion shaft i9 which drives a vertically aligned hollow shaftZ through multi-stage planetary gearing now to be described.

The latter gearing is enclosed in a stationary housing 22 spaced inwardly from the shell B2 and supported by the connecting frame member 2t which also serves to form the lower end of the inner housing. The upper end of the said housing is closed by a cap 2% through which shaft I9 enters, the entrance being sealed by packing 28 around the shaft.

The first stage of planetary gearing comprises a sun gear 35i on the lower end of shaft le and a plurality of planet gears 32 meshing with the sun gear and also with the internal teeth 34 of a ring gear formed integral with the housing 22. The planet gears, arranged in a circle about the sun gear in conventional fashion, are carried by a yoke 35 which has a downwardly extending shaft on which is xed the sun gear 3S of the second stage of planetary gearing.

The second stage is like the first in that it has planet gears meshing with the sun gear 38 and also with teeth t2 of a ring gear formed on the inside of housing 22. The planet gears of the second stage are carried by yoke i4 which has downwardly extending stub connected to the hollow shaft 2B for driving same.

As will readily be understood by those versed in the art, rotation of the sun gear 3i) causes planet gears 32 to travel in an orbit around the sun gear, turning yoke 3e and gear 33 at reduced speed. Gear 38 in turn causes planet gears to to travel in an orbit and rotate yoke lili and shaft 26 at still slower speed.

The high speed driving shaft IS is supported by a bearing 4S, and the low speed driven shaft 2i! by a bearing 58. An important feature resides in the provision of a bearing 50 to which the lower end of the intermediate speed shaft (i. e., the downwardly extending shaft of yoke 35) is secured by a bolt '52. Except for this arrangement, the upper yoke 36 could be perfectly free to shift axially relative the lower yoke and also relative the upper sun gear Sil, a situation which would give rise to deleterious bouncing, hammering and excessive wear on the parts; but this is prevented by the tying of the two yokes together as regards their vertical spacing, the arrangement nevertheless permitting the yokes to turn at different ring speeds as is required in their normal operation.

Ajixed to shaft I9 are the impellers 56.- of a multi-stage centrifugal pump 56. In operation, this pump draws liquid from the space in the well surrounding the unit, into the bailer through apertures Iii (see Fig. 2) then around baille l5 and through apertures I3 into pipe ID; the liquid is drawn downwardly through the pipe, then through the annular` passageway around the motor and through ducts 9 into the pump intak'e. After passing through pump 56, the fluid is discharged under pressure into the annular space 58 around housing 22 and flows through ducts 6i) and apertures 62 into the hollow shaft 2i); this connects to an extension shaft 54 which in turn directs the fluid into the bit to lubricate same and carry away the cuttings. As explained in detail in my co-pending application Serial No. 711,959, these cuttings are collected by sedimentation when they enter the bailer A2 through ports IQ.

The lower portion of hollow shaft 2!! is splined as shown at t. At the upper end of the splined section is a collar 6B keyed to the splines so that it rotates with the shaft. A split locking ring 'it on the shaft prevents downward movement of the collar, and upward movement is prevented by bearings l2 which comprise the main thrust bearings of my unit. The upper portion of the collar is of reduced diameter and between this portion and the stationary side wall of the connecting member 16, is a rotary seal 'i3 of any conventional or suitable design.

For lubrication and protection of the bearings thus far described, as well as of the planetary gearing and associated parts, the housing 22 is filled with lubricating oil or light grease introduced through nipple 3c. This nipple communicates with a duct t2 through which the lubricant may flow upwardly through and around bearing (i8, through and around the planetary gearing, filling ythe housing completely to the top cap 26. Duct 2 also leads downwardly to a piston chamber 3d which in turn, through apertures St, communicates with the annular space 38 around shaft 2e, and hence with the bearings 12.

Piston Sil in said chamber is urged upwardly by a coiled compression spring 92 supplemented by l the pressure of fluid admitted behind the piston through aperture 96. The latter aperture connects with a chamber QS formed on the exterior of the tool by a shallow recess covered by plate 93, this chamber being connected by a duct H30 with a fluid passageway maintained under pressure by the discharge of centrifugal pump 55.

In preparing my device for use, the lubricant is forced under pressure through nipple 8c until it fills the gear housing 22 (air being driven out through the relief valve lill during this process) and lls the space around bearing 12 down to the seal la. Spring .'12 compressed by the pressure applied to the lubricant during lling, and thus maintains the lubricant under pressure after filling has been completed. When the unit is lowered into the well and drilling is commenced, the well fluid pumped therethrough causes additional pressure to be applied to the underside of the piston, further pressurizing the lubricant as explained above.

Fluid seals 28, '58, m2 and H33 are provided for the purposes of preventing leakage at the points they protect, and although they are as `effective as it is possible to make them within the limits of commercial practicability, they may occasionally, as a result of wear or otherwise, nevertheless permit some small amount of liquid to pass. On one side of each seal is a zone containing well fluid under pressure; on the other side of each seal is a zone containing lubricant under a pressure exceeding that of said Well duid, at least by an amount equal to the force applied on the piston by spring 92. Accordingly, in the event of leakage at any seal, it will be leakage of lubricant into the well uid rather than vice versa, so there is no possibility of the lubricant protecting the gearing and bearings from being contaminated by intrusion of well fluid. The importance of this in preventing wear and damage to the working parts Will be self evident to those versed in the art.

The hollow extension shaft 64| is. rotatablyy andy sl'idably supported in a pair of` axially spacedl sleeve bearings |04.' and |05 each of which contains a sealing gland l.06. The space |100 between the bearings communicates through aperture H with a piston chamber ||I2 and this entirev space is lilled with lubricant: introduced through nippleA |'|4. On the opposite side of piston ||6 is a spring H0 exerting an upward force, the action of the spring being` supplementedby pressure. of well fluid admitted behind the piston through port |20. In the event there is. any leakage through seals |06 it. will be clear from the earlier explanation that, because. thev lubri-` cantr pressure exceeds well pressure by an amount equal to the force exerted by spring i8, theleak-A age will take the form of a slow extrusion of lubricant through the bearings rather than intrusion of well fluid into the bearings. This prevents the damage to the bearings which would take place if foreign matter were to enter same, and the supply or lubricant can be replenished periodically as needed through nipple I |34.

Secured to the upper end of shaft 64 is a heavy annular collar |20- which will be referred tohereinafter as the anvil or knocker; the bore of this collar has splines meshing with the splines 66- on the shaft 20, whereby the rotation of shaft 20 is transmitted to shaft 64V even though the knocker and its attached shaft travel axially relative toI shaft 20. Collar 68 acts as an upper stop for the knocker and an enlarged head |22 on bearing |04 acts as a lower stop. Since head |22 is stationary and knocker |20 often is rotating when they engage, the knocker carries on its underside a loosely supported bearing race |24 that actually contacts the head and minimizes the frictional resistance that otherwise would exist between the relatively rotating parts.

The knockerl is encircled by an annular baie |26 spaced inwardly from the wall of the main housing and extending vertically throughout the distance traveled bythe knocker. Atits bottom, the baffle is connected to the housing by a ring |28 butV at the top of the baiiie there is a compartment |30 connecting the space inside and outside the baiile. As knocker |20 travels downwardly along shaft 20, there is an increase in volumey ofthe liquid space inside baffle |26. which causes the fluid to be drawn over the baiiie from the outer annular chamber, the latter iluid being replaced by well uid drawn intothe housing through ports |32. As the knocker subsequently ascends, the liquid space within the baiile again decreases causing the excess fluid to be driven back over the bafiie and out, through ports |32. The admission and escape of liquid from the knocker chamber in this fashion insures that the knocker may move upl and down freelyat all times. The volume of the space outside of baiie |26 somewhat exceeds the maximum change in the liquid space inside the baiiie and since ports |32 are located nearv the bottom of the baiiie, none of the well uid enteringv through these ports (or the cuttings that may be. carried by such uid) ever reachesl the top. of the baiiie; in other words, no sediment or injurious foreign matter may reach the working parts housed within the baiiie. Sealing ring |34 in the knocker prevents entrance of foreign matter from the stream being pumped through the lshafts 20 and 6 4..

Any suitable type of bit may be screw-thread-v edly attached to the lower end of shaft 64, one form of core bit being shown in Fig. 4. This comprises an outer barrelk [3.6. rotating with the shaft; and having cutters |30 around its lower edge. An inner barrel |40 receives the upstanding. core` left by the.- downward advance of the cutters, this barrel being mounted on bearings |422 so that; it may remain stationary with the core despite therotation of. the outer barrel. Preferably; devices. are prcyidedon the inner barrel. permitting the entrance of the core but pre.- venting. retrograde movement of the core once ithas, entered;y these have not been` shown in detail for they are, conventional and form no part of the present invention., The well fluid pumped downwardly through shaft |34 passes through the annular space |44 between the two barrels t0 lubricate they cutters and drive the cuttings away therefrom, upwardly around the exterior of my unit4 to. the ports' I4 (Fig. 2) where they enter and are collected.

In lowering my unit on` its cable 5 into a well to drill: a core,it will be clear that the weight of the bit, shaft164. and knocker |20 will cause said shaft. to be extendedv from the lower end of the housing and` the knocker to rest on the enlarged head |22. When the `bit. reaches the bottom of the hole its advance naturally stops, but the operator continues to pay out the cable, allowing the balance ofthe unit to descend (during. the course of which shaft 64 recedes into the housing) until thev large collar 6.8 comes to rest. on knocker |20. The weight of the entire unit. now is imposed on the bit. Motor 6 is started, andwith the mass of the entire device urging the rotating bit downwardly, the cable 5 slowly is payedy out in order to drill the desired core and permitthe core barrel |40 to advance over the same; during drilling, well iiuid is circulated as outlined above and as described more fully in my co-pending application Serial No. '711,959 now U. S. Patent No. 2,609,182.

Motor 6. is halted when the drilling of the core is completed, it being understood that the core still is connectedat its base or root to the native formation so that it is necessary to break it loosel in order tol lift it to the surface for eX- amination. In the case of hard, impervious formation this obviously will require considerable force.

The operator nevertheless can accomplish the detachment ofthe core easily with my unit, simply byfreelingin cable. 5' with his hoist. The hoist is started slowly to avoid imposing undue strain on the cable as it commences to lift the heavy mechanism in the bore. hole; the fact that the core barrel |544 is securely anchored to the core, produces no substantial resistance to the initial upward movement of the device, since the shaft 64l simply is drawn out of the housing as the housing travels upwardly, the bit, lshaft and knocker |20 in effect being left behind. smoothly and graduallyv theV operator accelerates the upward' movement of the mechanism so that when shaft 64 finallyl reaches the limit of its extension, the upward momentum of the heavy apparatus', no-w moving quite rapidly, causes enlarged head |22 to strike the knocker with an abrupt hammer blow that, transmitted to the core, breaks the latter loose from its moorings and carries it along with the unit to the surface. All of the inertia of the heavy equipment, all the kinetic energy gathered during the initial upward movement,Y is. embodied in this blow,l and accordingly there is almost no perceptible increase in the tension on the cable 5 as the blow is struck. Ilhus have I eliminated the possibility of breaki? ing the cable by subjecting it to undue'strain in the courseY of removing the core from the bore hole.

It also will be noted that 1' have succeeded in combining all ol the working parts of my apparatus which are subject to wear (pump, gears, hearings, etc.) in a single, one-piece unit B which is readily attachable to and detachable from the driving unit A for servicing. 1n the event that any of these working parts require removal for replacement or repair, a substitute unit B may be employed with a motor unit in order to avoid the expense of rendering the whole tool idle while the service work is being carried out. The separability of parts A and B also facilitates transportation of the tool from the site of one job to the site of another, it being self evident that the overall length ci the tool when cornpletely assembled is too great to permit convenient shipping thereof. VV"From'the' foregoing it will be seen that this invention one well adapted to attain all of the ends and objects hereinbefore set forth, together with other advantages which are obvious and which are inherent to the apparatus.'

It wiil be understood that certain features and sub-combinations are of utility and may be employed without reference to other features and sub-combinations. VThis is contemplated by and is within the scope of the claims.

Inasmuch as many possible embodiments of the invention may be made without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and 'not in a limiting sense.

1. Submersible drilling apparatus comprising a housing suspended on a cable,` a rotatable and axially' movable vertical shaft extending through an aperture inthe bottom oi the housing, a bit on the lower end of the shaft', an enlarged head on the upper end of the shaft within the housing, stops above and below the head in said housing limiting the axial movement oi said shaft, auxiliary chamber'comrnunicating at its lower end with the space outside of the housing Vand communicating at its 'upper end with the space inside the housing, the volume of the auxiliary chamber exceeding the maximum change in volume in the housing caused by shifting of the shaft from its uppermost to lowerrnost position, and a prime vmover in said housing connected to said shaft for rotating same.

2. Submersible drilling apparatus comprising a housing suspended on a cable, a'rotatable and axialiy movable vertical shaft extending through an aperture in the bottom 'of the housing, abit on the lower end of the shaft, an enlarged head on the upper end of the shaft within the housing, stops above and below'the head in said housing limiting the axial movement of said shait, an annular baiiie in the housing encircling the shaft and spaced inwardly from the walls oi the housing to forman annular passageway communicating at its upper end with the space inside said baiile, means bridging the space between the baflie and the walls of said housing at the bottoinof baiiie to close said passageway, at least one aperture in the wall of the housing near the bottom of the baie connecting said passageway with the space outside of said housing, the volume of said passageway above said aperture exceeding the maximum change in lVolume inside `said baiiie caused by shifting of said shaft from its uppermost to lowermost position, and prime mover in said housing connected to said shaft for rotating same.

3. Drilling apparatus comprising a housing suspended on a cable, a prime mover in said housing, a shaft extending downwardly from said prime mover, said shaft comprising a pair of telescoping sections splined together, one of said sections connected to said prime mover and driven thereby, a bit mounted on the lower end of said other section, an enlarged head within the housing secured to the upper end of said other section, an enlarged stop secured on said one section for rotation therewith and adapted to be engaged by said head in the uppermost po- Sition of the latter, thrust bearings between said stop and the housing for transmitting the weight of the housing through said stop and head to said other shaft section, and a shoulder on the housing below said head for striking said head responsive to an upward movement of the housing.

Li. Submersible drilling apparatus comprising inner and outer housings rigidly connected together and suspended on a cable, speed reduction mechanism in the inner housing, a driving shaft extending from said mechanism upwardly through an aperture in the top of the inner housing, a prime mover connected to said shaft, a hollow driven shaft extending from said mechanism downwardly through an aperture in the bottom of the inner housing, a fluid seal between each of said shafts and said inner housing, said hollow shaft having an aperture coininunicating exteriorly of said inner housing with the space between said two housings, pumping means connected to said driving shaft for pumping uid through said space and into said hollow shaft, a lubricating and sealing medium within said inner housing, a piston having one face engaging said lubricating and sealing rnedum, and a duct extending from the other face of the piston to the space between said two housings whereby the fluid pressure in said space causes said piston to pressurize said lubricating and sealing medium.

5. Apparatus as in claim 4 including a spring urging said piston in a predetermined direction to augment the iorce applied thereto by said fiuid pressure.

ARMAIS ARUTUNOFF.

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